AB-DTPA浸提法研究上海中心城区绿地土壤有效态养分特征

摘要

采用 AB-DTPA 浸提剂联合电感耦合等离子体发射光谱法研究上海9个中心城区的509个绿地土壤的10种有效态养分含量。结果表明：上海中心城区绿地土壤有效态钾、钙、镁、锰和铁含量丰富；有效态磷、硫和钼普遍缺乏，部分土样有效磷、硫的含量超标与大量施用有机改良材料有关；有效态锌和铜均发生不同程度的累积，有些土样超标。不同时空的绿地土壤有效态养分含量与成土因素和人为活动有关。随着绿地建成年限延长，土壤有效锌和有效铜含量显著增加，但其他养分变化不显著。就上海不同区域而言，杨浦区、闸北区、浦东新区和徐汇区有效态养分含量相对较低；长宁区、静安区和黄浦区有效态养分含量较高；虹口区和杨浦区锌、铜累积程度高。公共绿地与公园土壤养分含量相当；道路绿地的有效态钾、硫、镁显著高于前两者，但有效态锌、铜和铁含量显著低于前两者。随着土壤剖面加深，土壤有效态硫、镁和钼含量呈增加趋势，而有效态磷、钾、锰、锌含量稍许降低。AB-DTPA 浸提法适用于土壤中大部分有效态养分的快速分析，建议在全国推广应用。%Ten kinds of available nutrients in 509 greenbelt soil samples from 9 administrative regions in Shanghai were analyzed by AB-DTPA extraction and inductively coupled plasma (ICP) atomic emission spectrometry. The results showed that the soils were rich in available potassium, calcium, magnesium, manganese and iron, but lack of available phosphorus, sulfur and molybdenum. The contents of available phosphorus and sulfur in some samples were exceeding the corresponding standard, which might be related to the application of large amounts of organic-improved materials. Both available zinc and copper were accumulated in different levels, while some soil samples exceeded the corresponding standard. The available-nutrient contents in the greenbelts in different periods and regions might be related to the soil-forming factors and human activities. The contents of available zinc and copper in soil increased significantly with the extension of year since the greenbelts were constructed, but the other nutrients had no significant difference. In terms of different administrative regions in Shanghai, the contents of available nutrients were lower in Yangpu District, Zhabei District, Pudong New Area and Xuhui District, but relatively higher in Changning District, Jing’an District and Huangpu District. Hongkou District and Yangpu District showed the highest accumulation degree in zinc and copper. The contents of soil nutrients were equal between the public green space and the park. The contents of available potassium, sulfur and magnesium in road green space were significantly higher than those in the public green space and in the park, but the contents of available zinc, copper and iron were significantly lower. With the increase of soil depth, the contents of available sulfur, magnesium and molybdenum were increased, but those of available phosphorus, potassium, manganese and zinc were slightly decreased. The AB-DTPA extraction method is suitable for rapid analysis of most available nutrients in soil and can be used widely in China.